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Author Topic:   putting my car on a diet
gould
Dirt Forum Champ
Total posts: 730
posted September 13, 2005 05:52 PM  
We are going to try to lighten a few things on my car this winter. What we got so far is going to the pinto front end and switching to plastic brake lines. My car is 2660 after the main with me in it. I weight 220. How much will i lose with those two things changed? what other areas can i look at? i know i could probably shed a few pounds in the driver compartment, lol. this is for a imca modified, 96 harris chassis with chromoly front. Thanks

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FlyNLoIMCA17
Dirt Forum Champ
Total posts: 753
posted September 13, 2005 07:00 PM  
The pinto spindles are lighter than the metrics (I suppose thats what ur runnin'??) BUT with the pintos you have to run the metric caliper adaptors and the rotors (Granadas) are heavier so when you add the weight of the complete assemblys the weight difference is VERY slim to none! I run pinto spindles but because they are much, much stronger. No more bent steering arms with them. If you do bend one there will probably be a lot more bent besides them.

The plastic brake lines.....never ran them so I don't know but they don't look very durable to me??? I have seen some on here say they are good. You'll have to talk to them.

I was doing this same thing last year. My car weighs like 2200 or 2300 w/o me in it and thats also with 75lbs of lead added. So mines pretty light already but I was looking for more rear weight %. After examining the nose, I couldn't do anything without cutting out bars and replacing them with smaller ones and I didn't really want to do that. Ended up moving around some lead and other stuff to make the weight where I wanted it.

I know that really doesn't answer your question any but I figured you might want to know about the spindles before you spent all that money to swap em' over!

gould
Dirt Forum Champ
Total posts: 730
posted September 13, 2005 07:24 PM  
I have the impala spindles now

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zeroracing
Dirt Forum Champ
Total posts: 1875
posted September 13, 2005 07:46 PM  
Go back to steel lines, I am hardcore against plastic for many reasons.
But Other Ideas, would be
Aluminum power steering pump? Change spindles to pinto, go with a .065 thick wall front bumper(super light) 1.5 outside dia. Look for some overkill heavy tube and replace with lighter(like a whole bunch of square turn into some round, but saftey first). Do you run gas or alky? If on gas go to a smaller fuel cell.
Light battery, like Dui sells, Light seat, No right side nerf bar, no left side nerf. Smaller rear bumper(some cars have large wrap aroundo ones).
Just look around, you can find a few small things and they add up.
Also diet, most drivers take offense to that if I tell them that, but its cheaper for you too loose a few pounds than to buy light weight parts.
alsowhat kind of tranny are you running?

[This message has been edited by zeroracing (edited September 13, 2005).]

Racer X
Dirt Freak

Total posts: 256
posted September 13, 2005 07:50 PM  
Single row radiator, light seat, lite gauges,alum lug nuts. Using the right size bolt for the application(Like using a 3/8 bolt when a 1/4 would work, lite spool and gears.Every little bit helps, I plan on knocking off a few pounds off our car over the winter.Be sure not to sacrifice duribilty for a little weight, we tried the alum weight jack bolts one year, didn't work too well.

CUSTOMPERFORMANCE
Dirt Forum Champ
Total posts: 1172
posted September 13, 2005 07:54 PM  
Pinto spindles and granada rotors verses the impala is about a 30-50 lbs weight difference.

gould
Dirt Forum Champ
Total posts: 730
posted September 13, 2005 08:02 PM  
i run a bushore powerglide

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FlyNLoIMCA17
Dirt Forum Champ
Total posts: 753
posted September 13, 2005 09:17 PM  
Have you guys seen the tubular bolts?? They are illegal in IMCA(I think) but a friend of mine works for a local race shop and he said they put the tubular bolts on a late model. Replaced all the bolts on the chassis and it dropped 56 lbs. I was wondering just how strong these were? I know you can also get tubular titanium bolts but I'm sure they are even more over priced than the steel ones.....

Also on this subject, whats the difference in weight between a regular 2" body shock and the small bodied shocks like the bilstein's or blue afco's?? Might want to look into that also.

Oh, yeah I should have said in my first post that the pinto weight to the metric, I meant small metric. I don't know about the big metrics. And with you running the impalas I'd definately go to the pintos. You can also look at your driveshaft diameter and possibly decrease it. Like running one of the "dog bone" styles if your running un-sanctioned.

FlyNLoIMCA17
Dirt Forum Champ
Total posts: 753
posted September 13, 2005 09:21 PM  
I just went to your website and noticed your already running the small Afco shocks up front. Also I noticed you kinda have too many bars in front of the driver IMO. You could probably take out about 15 of those LOL!! I think the rule is 3 or 4 minimum. Thats driver protection, so its up to you on that part! It may not be much weight but like was said before a little here, a little there and it adds up.

2nd2none
Dirt Forum Champ
Total posts: 755
posted September 13, 2005 11:48 PM  
doesn't the bassett wheels weight a bunch also? Aero or Real makes 19# wheels. I ran the tubular bolts on my sprint car this year and only had one failure. I snapped the head of a 1/2" bolt when I was checking for tightness. This is a known issue with tubular bolts because they weld the hex head on which weakens this area. I talked to Mike Clark (dirtworks) about running tubular bolts on a 2300 lb modified, he said they have ran them before with no problems. There is no such thing as a tubular titanium bolt, just a titanium bolt. If it was me I would rather spend the money on the large titanium bolts (1/2" and larger) and use tubular for the smaller stuff.

Also, as Racer X said, make sure you aren't over doing it on the size of bolt vs. application required and make sure you aren't using a 2" long bolt when a 1 3/4" will work or cut all excess off with a dotco.

Knocking weight off is 1) time consuming and 2) can get expensive

One more area to look at is firesuit and helmet. I used to run a Bandit helmet and my new one is a Vudo. I can tell you there is probably 3 or 4 lbs difference between the two. (vudo is lighter, but $300+ more expensive) CarbonX made firesuits are ultralight and have the same protection as a nomex, but then again are alot more $$$

FlyNLoIMCA17
Dirt Forum Champ
Total posts: 753
posted September 14, 2005 12:08 AM  
oh, my bad. I was thinking I saw some titanium tubular bolts somewhere....guess not. I wonder why they don't make em'?? Titanium is stronger and lighter than steel, just makes sense for a company that makes steel ones to make titanium ones.

The company that makes the tubular bolts is Race Bolt, there may be others but this is the only one I know of and their bolts are made of 4130 Chrome Moly (maybe I confused chrome-moly w/ the titanium LOL!)

psycho47
Dirt Full Roller

Total posts: 48
posted September 14, 2005 05:14 AM  
I switched from a Bushore to a Bert with the Bert lightweight bellhousing and it saved 30 to 40 pounds, not to mention gettring rid of all of that rotating weight by using the reverse mount starter and getting rid of the starter ring.

dirtbuster
Dirt Forum Champ
Total posts: 2007
posted September 14, 2005 07:32 AM  
Use GM metric rotors on your pinto spindles and save a few more pounds ea over the granada rotors.

Use lighter gage aluminum for your body. I think I figure up one time going from roughly .040 to .028 saved like 20# on the car.

If your on alky got to the lightweight single row radiator thats worth prob 8# anyway maybe more.

I wouldnt switch to plastic brake lines just for weight savings, too many downfalls to me.

dooby
Dirt Roller

Total posts: 20
posted September 14, 2005 04:07 PM  
Like you said it is a hole lot easier and cheaper to lose that big belly. and it would be easier to get out of car.


gould
Dirt Forum Champ
Total posts: 730
posted September 14, 2005 07:26 PM  
look whos talkin' doob!!

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viper3244
Dirt Full Roller

Total posts: 57
posted September 14, 2005 09:05 PM  
Look at rotating weight, I believe its the biggest bang for your buc! Lighter tranny (ball spleen wich would also be shorter drive shaft) mini spool. Things like this reduce your weight but also will increse your horsepower. As stated above single core radiator lightweight seat are also good ideas.NEVER lighten things like a plug for short bars or j-bar mounts, not only is it unsafe but if you brake one it usually repairs cost's lots to fix. As far as the plastic brake lines, I have been using them for 2 years with no problem. I don't use them because of weight just because the ease. No bendeing or kinks. If you switvh to them be consious of where you run them. I always keep them on the backside of the tubes and where they won't get damaged in minor tangle ups. good luck.

Kromulous
Dirt Forum Champ
Total posts: 796
posted September 15, 2005 06:51 AM  
1 pound of roatating mass equals 10 horsepower, 10lbs of mass equals (non rotating) 1 horse power.

Thats the tale i was told anyway. I figured up in the rear end, 13.7lbs stock carrier, and mini spool, ultra light spool 6 lbs, light weight gear is what 3 lbs lighter? and gun drilled axles? maybe 3 or 4?

Thats a total of around 14lbs, 140 hp. I know we could all use 140 hp.

oldfordmod
Dirt Full Roller

Total posts: 46
posted September 15, 2005 12:03 PM  
Krom: According to Herb Adams is his book "Chassis Engineering, chapter 15, Rotating Inertia", Chassis rotating weight (Wheel speed) is = to 3 times the reduction of overall non rotating weight. Driveline rotating weight (engine speed) is worth 15 times non rotating weight. The only part of driveline weight in the rear end is the pinion gear and yoke so 140 HP might be a little high.

Kromulous
Dirt Forum Champ
Total posts: 796
posted September 15, 2005 12:11 PM  
Well, yeah but the point is valid. Your point is more scientific, mine is just easy to remember, and a pretty good rule of thumb. Just dont take the actual numbers to the bank.

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